HP SCOPEOK so I took it apart for a good visual inspection inside, then took for a test ride to check that all controls/keys/knobs work, check for proper operation of the basic functionnalities and see if I can find any problem in the way it works.
VISUAL INSPECTIONEasy to open up. A screw to remove and the module at the back comes off. Then just two Torx screws at the back in lower left and right corner, and the cover comes off.
Searching to signs of monkey damage or the scope being put together hastily from a bunch of (defective...) random boards.
- No loose screws or anything wandering inside the scope, good beginning.
- Found that the small board plugged at the back of the CRT neck, was crooked, its edge wasn't perfectly horizontal. Thought maybe monkey put it back incorrectly, maybe after trying to recap the CRT area to fix the squashed display syndrome but.... no, was being and mouth : the white silastic that secures that board to the glass of the CRT neck.. was still intact.
- Looked at all the electrolytic caps, searching for signs of past rework, or bulging or leaky caps... nothing. They all look original and healthy, visually at least I mean...
- Minor/normal amounts of dust in the PSU area, though there was a huge hairy ball on that board... and lots of fluffy stuff sticking to the back of every rotary encoder of the front panel...
- Main board - Power rails are nicely identified on the silk screen, all grouped together at the edge of the board. It says -5V, 5V, -15V and +15V. How original !
Found also a couple of 3 pin voltage regulators on that board, a 317 and a 337.. this thing is state of the art eh ?!
Well at least it's stuff I can recognize and fix easily, so that's good !
Didn't find any aluminium electrolytic cap, good ! Found some tantalum though... but only 5 of them. A big one in the CPU area of the board, and then a group of 4 small ones far away from the first one, in the area of the front end for the digital / logic input connector.
Found one NVRAM and one EPROM, so not a whole lot.. maybe the F/W is compressed and gets uncompressed into RAM when the thing boots ?!
Either that or the HP F/W guys are very good to cram lots of stuff into a single EPROM !
Noticed that the 5 heat sinks mounted on big square packaged chips... are all badly crooked ! Just like the CRT neck board then ! So I felt relieved, it's "normal" HP stuff of the era, it's not a bug it's a feature !
Then looked for physical damage... since it's common on these it seems.
- No obvious crack on the main board
- No signs of rework or monkey putting his dirty hands inside that scope...
- The brightness control knob that I found initially, upon unpacking, a bit dislodged... well looks like it simply needed reseating into the pot. I don't see anything wrong with that pot or knob when viewed from inside... so that looks like it was a red herring, fortunately ! Just me being overly paranoid and wary...
So... that all looks excellent I thought ! All these missing knobs were not at all indicative of an underlyng horror story !!!
See ?
TEST RIDESo I put the cover back on, plugged the I/O module back onto the back of the scope, and fired it up !!!
In short : it all appears works perfectly !!!!!
-CRT is crisp and very stable, rock solid. Not undulating or fuzzy. It's perfect.
Brightness, just fine. Can vary smoothly from dark to super bright.
- All the buttons below the CRT work, though I did notice that sometimes they can hard at hearing when you press them downward, but respond reliably if you push on them at 45° angle, with a combined forward motion. If you see what I mean... You press down and a bit forward at the same time. They appear to like that...
But anyway, unlike BD had with his, these buttons are not broken, they all work, so that was a relief right there.
- BNC sockets are OK, firmly in place.
- All encoders / knobs appear to be working fine and reliably, they don't need cleaning (despite all the dust collecting on them...).
- Both channels work, I can display a signal, change attenuator settings, vertical position etc...
- the HP original x10 probes are detected properly by the scope, it changes the Volts / DIV readout accordingly.
- Automatic measurements work.
... basically all the basic / obvious stuff works, could not find anything blatantly wrong with it, on this first quick test. I guess we shall see in the longer term as I get to spend time using it.
So in short.... this scope is a 100%
WINNER WINNER CHICKEN DINNER from top to bottom !!!
Only slight thing I found "wrong" with it, if I dare, is a sliiight geometry problem with the picture on the CRT. It's not even visible on my pictures I think, but it is in the flesh. Problem is the picture is not perfectly rectangular. It is more like trapezoidal, with the upper edge being a bit shorter/narrower/squeezed than the lower edge, which looks fine. Looks a bit like the intro text in the old Star Wars movie...
But it's very slight. I will look in the manual, calibration procedure section to see if there might be trimmer in the CRT board that looks after that particular aspect of the geometry. If not, then I guess some proper troubleshooting is on order, which would be fun and interesting and educational (I know squat about CRT circuitry...), since we have the schematics for this scope. Well, have not yet looked a them in detail, so I am hoping they are complete, including the CRT stuff and power supply, not just the main board...
USING IT...My first HP scope so everything is new to me, it's all alien to me compared to my usual Tek scopes...
Impressions...
Well :
- Fan is pretty quiet as it is. Thinking though that a modern / fresh fan could be even quieter, so might give that a try. Noise level is important when sit 12 hours non stop at the bench in front of the scope, working on your latest gizmo.
- It boots very fast, much like my Combiscope, and unlike my Tek TDS scope that takes 60 seconds (I timed it). So that's a very good point.
- It's very responsive and smooth going when you use the vertical or trigger level controls.
- The encoders for the trigger level is excellent, it feels almost like an analog pot. It's incredible, they nailed the "acceleration" of the thing perfectly (as well as the mechanicals of it, the resistance it opposed to rotation is just nice), like I have never seen anywhere before. That couple with the aforementioned responsiveness, makes you feel like your using an analog scope. It's really incredible, very enjoyable. Ergonomics is an important part of using any bench piece of TE, especially a scope since you interact so much with it when working on stuff. In contrast, my Combiscope is a total disaster. All digital controls too (even the brightness for the CRT), but the acceleration management is disastrous : if you turn a knob slowly, nothing happens, and if you turn it faster... it skyrockets to the other side of the screen/men whatever. It's an ON/OFF switch. The "feel" of the knobs aren't as good either. Not enough resistance to motion, and a slight radial play in the knobs. In short they feel a bit cheap...
So I was therefore immediately able to notice and appreciate ow HP got that bit just right....
- The overall layout of the front panel is simple and efficient, it's easy to find stuff, looks simple, not spaceship like my old GOULD 1604 for example.
- There is unexpected sophistication and refinement in the UI of this scope, I was surprised ! --> when I was in the measurement menu to try the automatic measurement functionalities, see what was available, I noticed that every time I modify something in there, the read out at the bottom is updated using some animation ! The new/updated content appears from the right edge of the screen, and slides horizontally towards the left, in a perfectly smooth / top quality fashion ! Makes it look like million dollars state of the art machine !
- I miss something all Tek TDS scopes have : a prominent, dedicated " Clear Menu " button near the CRT, to get out of any sub-sub-sub menu you are in, and get you back to your signals. Because more often than not you can easily search for stuff in the menu structure, "get lost", and wanting to go back to the top level, or exit the menu entirely, but are afraid to touch anything for fear you might screw things up... you just want an easy and safe and quick way out of the " menu hell " so to speak.
The HP does not provide that, that I could see anyway.
- BTW the lack of knobs was hardly a bother, all digital controls / encoders of course, so requires little force to rotate. After a few seconds you don't even feel the need to have knobs, somehow ! It's just effortless.
CONCLUSIONSo that's it, looks like there is absolutely nothing wrong/fishy about this scope ! Despite all thje missing knobs, it's was not Frankenstein unit made from a bunch of random defective parts loosely taped together. Nope, it all looks intact and "legit" in there. Does not look like it was dropped, works fine, no problems with the BNCs, no problem with the squashed picture on the CRT, none of the usual HP problems Dwagon and BD have been exposing. I am truly in luck !
I declare this scope a 100% winner.
So now I need to RTFM and explore its functionalities. Play with the deep memory, the Megazoom stuff, explore the logic inputs stuff of course... had a quick look at the trigger menu, and saw you can trigger from a logic edge, or a logic pattern. So that's kinda cool, and the main point of an MSO I guess...
Will RTFM to learn all about it of course.
A few piccies....
-group-therapy-thread/?action=dlattach;attach=1512994;image)
Home
Help
Search
Login
Register
Topic: Test Equipment Anonymous (TEA) group therapy thread (Read 15532436 times)